If you are facing a DUI charge in Arizona, one way to avoid a conviction is by keeping the prosecution’s evidence out of court. If prosecutors can’t use their evidence against you, they won’t be able to prove your guilt beyond a reasonable doubt.

This means you will be entitled to walk free without facing the life-altering consequences of a DUI conviction.

How do you keep the prosecution’s evidence out of court? While several issues can render key evidence in a DUI case inadmissible, your available options depend on your case’s specific facts and circumstances. To be clear, there is no guarantee that you will be able to challenge the prosecution’s evidence and avoid a conviction successfully. But, if you have grounds available, you should assert them, as this could be your best (or only) option for avoiding unnecessary consequences.

5 Ways to Keep Evidence Out of Your Arizona DUI Case

With this in mind, here are five potential ways to keep the prosecution’s evidence out of your Arizona DUI case:

1. Assert Your Fourth Amendment Rights

One option is to assert your Fourth Amendment rights. Whether you are a U.S. citizen or a U.S. resident, you are entitled to protection against unreasonable searches and seizures. In the context of a DUI case, the police cannot stop you without “reasonable suspicion,” and they cannot arrest you without “probable cause.” If the police violate either of these protections, this can render all of the state’s evidence against you inadmissible in your DUI trial.

When do the police have “reasonable suspicion”? What does it take to establish “probable cause”? These are complex questions that do not have easy answers. When you speak with an experienced DUI defense attorney, your attorney will work with you to examine all of the facts and circumstances of your DUI case to determine if this is an option you have available.

2. Assert Your Fifth Amendment Rights

A violation of your Fifth Amendment rights could also entitle you to have key evidence excluded from your DUI case. The Fifth Amendment establishes the right to remain silent. While prosecutors can use any statements you make voluntarily, they cannot use any statements obtained violating the Fifth Amendment (though it is up to you to ensure this doesn’t happen).

Once the police place you in custody, they must read your Miranda rights before interrogating you. The U.S. Supreme Court has determined that this is a requirement under the Fifth Amendment. If the police interrogated you in custody without reading your Miranda rights, any statements you made after the violation may be inadmissible in court.

3. Expose a Break in the Chain of Custody

To be capable of proving your guilt beyond a reasonable doubt, evidence needs to be reliable. If prosecutors cannot establish a transparent chain of custody for a piece of evidence they intend to present in court, this inherently raises questions about its reliability.

In DUI cases, this issue primarily comes up concerning blood and urine samples. If you provided a blood or urine sample, prosecutors will try to use it to prove that your blood alcohol concentration (BAC) was over the legal limit. But what if they cannot prove that the sample is actually yours? This is a valid question in many cases, and if it is not absolutely clear that your BAC is being presented, it should not be used against you.

4. Expose a Failure to Disclose Key Evidence

When facing a DUI charge in Arizona, you have the right to know what evidence prosecutors intend to use against you in court. You also have the right to see if they have any exculpatory evidence (evidence that is favorable to you) in their possession. If prosecutors fail to disclose evidence as required, this issue can render their evidence inadmissible in court.

This protects two more of your constitutional rights. The obligation to disclose harmful evidence protects your right to confront any witnesses against you and ensures you can build an informed defense. The obligation to disclose exculpatory evidence protects your right to due process—helping to ensure that you are not prosecuted under circumstances in which prosecution is not warranted.

5. Raise Issues with the Evidence Itself

If you are facing a DUI charge, you may also be able to keep evidence out of your case by raising issues with the evidence itself. Several problems can render specific evidence unreliable or inadmissible for other reasons. For example:

  • Breathalyzer Results—If you took the breathalyzer on the side of the road, your BAC reading could be unreliable for various reasons. These range from improper calibration of the breathalyzer device and inappropriate administration of the test to alternate explanations for your high BAC.
  • Field Sobriety Test (FST) Results—Various issues can render FST results unreliable and inadmissible. These, too, can range from issues with the testing procedures to alternate explanations for why you “failed” the tests.
  • Police Officer Testimony—Several issues can render police officers’ testimony unreliable and inadmissible, from making misguided assumptions to trying to cover up other mistakes.
  • Your Admissions—Even if you admitted to drinking and driving before the police were required to read your Miranda rights, your admission could still be inadmissible in court. As we have discussed, there could be various reasons why your admission doesn’t warrant a conviction.

Discuss Your Case with an Experienced Phoenix DUI Defense Attorney in Confidence

Are you facing a DUI charge in Arizona? If so, we encourage you to contact us promptly for more information. To confidently discuss your case with an experienced Phoenix DUI defense attorney, call 480-897-8737 or tell us how we can reach you online now.